Bearing with a lubrication fitting

ABSTRACT

A longitudinal lubrication passage and a cross hole in the inner race are used for lubricating rollers in the annular space between the inner race and the outer race. At least a portion of the longitudinal lubrication passage is non-circular. The cylindrical shank of a lubrication fitting is press fit into the non-circular longitudinal lubrication passage portion.

This invention relates to bearings. More particularly this invention isa bearing of the track roller or cam follower type which includes alubrication fitting of a particular structure to permit the lubricationof the rollers and also permit the attachment and removal of the bearingfrom a bearing support.

In a typical track roller or cam follower type bearing, a longitudinallubrication hole is often drilled through the stud or inner race member,generally with a cross hole added to provide access to the racewaysurface for lubricating the bearing elements. The lubrication holes areprovided for the user who may wish to re-lubricate the bearing duringits life cycle. If the user needs to re-lubricate the bearing andexclude contaminates, it is necessary to insert a lubrication fitting inone end of the longitudinal lubrication hole and to plug the endopposite the end being lubricated. The lubrication fitting normally hasits own internal check valve which keeps the lubricant in the bearingand excludes contaminates while allowing the lubricant to enter.

It is a common practice to provide a hexagonal socket in the head end ofthe track roller bearing inner member or stud. The hexagonal socket isused to attach the bearing to a threaded hole in a mounting plate or toprevent the stud from turning when a nut is applied to the stud end.When the bearing is provided with a hexgonal socket, the socket is leftblind or closed and access for re-lubricating the bearing is onlyavailable from the opposite end of the stud. The invention to bedescribed herein includes a lubrication fitting in a hexagonally shapedsocket of the stud with the lubrication fitting central bore leadinginto a lubrication passageway in the stud of the bearing. Thus accessfor lubricating the bearing is available at both ends of the bearingstud.

The invention to be described herein its particularly useful in a camfollower type bearing and will be described in detail with regard to itsuse in a cam follower. However, the system can be used in other bearingtypes which employ lubrication system.

Briefly described the invention includes an inner member and an outermember with a plurality of rolling members located in the annular spacebetween the inner member and the outer member. The inner member has alongitudinal lubrication bore, and a cross-hole extending radially fromthe longitudinal lubrication bore to the annular space. At least aportion of the longitudinal lubrication passage is non-circular. Alubrication fitting having a cylindrical shank is press fit into thenon-circular lubrication passage portion.

The invention as well as its many advantages may be further understoodby reference to the following detailed description and drawings inwhich:

FIG. 1 is a side view, partly in section, showing a preferred embodimentof the bearing mounted for movement along a bearing support; and

FIG. 2 is a sectional view on an enlarged scale taken along lines 2--2of FIG. 1 and in the direction of the arrows.

In the various figures like parts are referred to by like numbers.

Referring to the drawings and particularly to FIG. 1, the roller bearingcam follower 10 has a threaded portion 12 at one end of the stud orinner race 14 so that the entire bearing may be secured to a suitablearm 16 for transmitting motion. Stud 14 has an integral flange 17 at oneend and adjacent this flange there is a bearing surface 18 having areduced diameter from the outside diameter of the flange 17 and actingas the inner raceway of the bearing. A plurality of rollers 20 aredisposed about the stud 14 on the bearing surface 18. The rollers areaxially kept in position by the end flange 17 and annular end plate 22.

An outer member 24 has a bore 26 and counter bores 30 and 32 in itsaxial ends. The raceway 34 of the outer member 24 is positionedlengthwise between the counter bores 30 and 32 and bears upon therollers 20. When the arm 16 is moved, outer member 24 rotates about therelatively fixed stud 14 as the outer member rolls along the platform 40of a bearing support.

In accordance with the invention, the inner member 14 is provided with acentrally located longitudinal lubrication passage 42. A cross-hole 44extends radially from the longitudinal lubrication passage 42 to therollers 20 contained in the annular space between the inner member 14and the outer member 24.

At least a portion of the longitudinal passage 42 is non-circular incross section. In the preferred embodiment of FIG. 1 the non-circularcross sectional portion 46 (see FIG. 2) is hexagonal in cross section.The hexagonal portion consists of six flat surfaces 48 connectedtogether at their ends to form the hexagonal cross sectional portion 46.

The hexagonal portion 46 is preferably located in the head of the innermember or stud 14 at the lubrication passage 42 entrance. A lubricationfitting 50 is placed into the hexagonal portion 46 by a press fit. Thelubrication fitting 50 has a shank 52 provided with means for axiallyretaining the fitting 50 in the longitudinal lubrication passage 42. Theretaining means consists of annular projections or serrations 54.Because the lubrication fitting 50 is press fit into the hexagonalportion 46, the serrations 54 tend to bite into the flat surfaces 48 ofthe hexagonal portion to retain the fitting in the passageway 42 againstaxial movement. The press fit also deforms the shank 52 of thelubrication fitting 50, as shown in FIG. 2, to approach the shape of thehexagonal portion 46. Thus, the lubrication fitting 50 will not turnwith respect to the inner member 14 when a turning torque is appliedagainst the lubrication fitting 50.

When the lubrication fitting 50 is press fit into the longitudinallubrication passage 42, the longitudinal movement of the shank 52 islimited by contact of the flat surface 56 of a non-circular portion 57extending radially from the knob 58 of the lubrication fitting 50 withend flange 17. Preferably the radially extending portion 57 ishexagonally shaped and consists of flat surfaces 62 having their endsinterconnected to form the hexagonal radially extending portion.

In operation a properly shaped wrench is applied to the hexagonal shapedportion 57 of the lubrication fitting 50 to hold the inner member 14against rotation as the nut is applied to the threaded end of the innermember 14 or to remove the bearing from the arm 16 when desired. Whenre-lubrication is desired, all that need be done is to apply the greasethrough the hole 43 (see FIG. 2) in the lubrication fitting 50.

I claim:
 1. A bearing comprising: an inner member; an outer member ofgreater inside diameter than the outside diameter of the inner memberthus providing an annular space between the inner member and the outermember; a plurality of rolling members in the annular space, said innermember having a longitudinal lubrication passage, at least a portion ofsaid longitudinal lubrication passage being non-circular, and across-hole extending radially from the longitudinal lubrication passageto the annular space; and a lubrication fitting having a cylindricalshank press fit into said non-circular lubrication passage portion.
 2. Abearing in accordance with claim 1 wherein: the lubrication fittingcylindrical shank has projections adapted to axially retain thelubrication fitting in the longitudinal lubrication passage.
 3. Abearing in accordance with claim 2 wherein: the projections are annularserrations.
 4. A bearing in accordance with claim 3 wherein: thenon-circular lubrication passage portion is hexagonal.
 5. A bearing inaccordance with claim 4 wherein: the hexagonal portion is at thelubrication passage entrance, and the lubrication fitting has a portionextending out from the lubrication passage, such portion having anon-circular outer surface to permit the turning of the inner member bythe application of a properly shaped wrench to said non-circular outersurface.